Proliferin 1生物特性之探討
Biological Characterization of Proliferin 1
Date Issued
2004
Date
2004
Author(s)
Hsieh, Heng-Yu
DOI
zh-TW
Abstract
Proliferin (PLF) is a secreted glycoprotein in the prolactin-growth hormone family. PLF1 has been shown to be expressed in the fibroblasts but was suppressed during myogenic differentiation. PLF is actively involved in cell proliferation and selectively represses myogenic-specific transcription that modulates multiple muscle-specific genes. Previously, we have found that PLF1 mRNA was differentially expressed during adipocyte differentiation. To further elucidate the role of PLF1 protein in the biological system including adipogenesis, body weight regulation and cancer cell proliferation/metastasis, we aimed to express recombinant proteins, producing a polyclonal antibody, and evaluate the level of protein expression of PLF1 in various biological systems.
We have cloned the full-length cDNA of the PLF1 into prokaryotic expression vector and found that the expression of the protein was predominantly insoluble and in the inclusion bodies. We have solubilized this protein and performed protein refolding to obtain active protein with success. Antibodies were obtained by immunizing rabbits via intrasplenic injection of this soluble protein. With monitoring of the titer of antibody, we found immune serum at 4th week contained a high titer of antibody as evidenced by Immunoblotting analysis on the recombinant proteins.
To explore the protein expression of PLF1 during adipogenesis, we found the expression of PLF1 protein increased with adipocyte differentiation, consistent with the expression of mRNA analyses by RT-PCR. This expression pattern is quite contrast to myogenesis. Since PLF1 is a secretory protein, we tried to detect this protein in the serum of obese before and after weight reduction surgery. Unfortunately, we could not detect PLF1, possibly due to the low concentration of this protein or the quality of the antibody. However, we found a 45-kDa protein reactive to our antibody that showed difference in the plasma samples of obese subjects after surgery. Similarly, we could not detect 24-kDa PLF1 in the serum of mouse sera from the implanted cancer with and without metastasis. But, a 45-kDa protein was also detected in those samples.
In conclusion, we raised the PLF1 antibodies and showed the increased protein expression of PLF1 during 3T3 adipocytes differentiation. The level of PLF1 in the serum could not be detected possibly due to low concentration of this protein or the poor sensitivity of the antibody. Further purification of the specific antibodies is warranted for future investigation.
Subjects
分泌性醣化蛋白質
PLF1
SDGs
Type
other